There ought to be a way.
There (another) way .
SumTotal ELIS can serve as a true LMS by assigning a curriculum, tracking learner progress, recording grades, etc., while Moodle would serves as a VLE by delivering content, providing a collaborative learning environment, and assessing.
More about Moodle Partner Remote-Learner's ELIS for Moodle . It's open source, and even fully hosted, supported, and managed the cost is a good bit less than SumTotal.